Abstract 13557: Impact of Cardiac Resynchronization Therapy on Clinical Outcomes in Transthyretin Amyloid Cardiomyopathy

Abstract

Introduction: Due to conduction disease and dyssynchrony in transthyretin amyloid cardiomyopathy (ATTR-CM), cardiac resynchronization therapy (CRT) may be beneficial. We aimed to determine the impact of CRT on clinical outcomes in ATTR-CM. Methods: We studied 116 consecutive ATTR-CM patients, 23 of whom underwent CRT (70% CRT + defibrillator, median 10 months (IQR 4-20) from ATTR-CM diagnosis). Outcome was a composite of 1 st cardiovascular hospitalization or all-cause mortality. CRT was treated as a time dependent co-variate and entered into multivariate Cox proportional hazards model. Results: Both groups were similar at diagnosis except for a higher proportion with atrial fibrillation (AF) and lower ejection fraction among those who underwent CRT ( Table 1) . CRT indication in 80% was progressive LV dysfunction with wide QRS [mean 152 ± 36 msec] and the remaining at time of AV node ablation for AF. Half of CRT group were ≥ NYHA class III at device implantation. Older age, higher National Amyloidosis Cohort (NAC) ATTR stage, and not taking tafamidis were significantly associated with the outcome. On multivariate analysis, CRT was associated with a HR of 0.6 (95% CI: 0.32 - 1.16) for all-cause mortality or cardiovascular hospitalization after adjusting for age at diagnosis, NAC ATTR stage, and tafamidis use ( Figure 1). Conclusion: CRT implantation maybe associated with improved outcomes in ATTR-CM. Larger prospective randomized, sham-controlled trials are warranted to confirm these findings.